1. Field of the Invention
The present invention generally relates to radio systems providing wireless voice and data links in networks, and more particularly, to a cognitive radio engine architecture which is capable of working under changing and unanticipated circumstances and in the presence of hostile jammers and interferers. The cognitive radio engine is capable of continuously adapting to its environment to conserve resources, such as radio frequency spectrum and battery power, in those applications where those resources are at a premium.
2. Background Description
Most traditional radios have their technical characteristics set at the time of manufacture. More recently, radios have been built that self adapt to one of several preprogrammed radio frequency (RF) environments that might be encountered. Cognitive radios go beyond preprogrammed settings to operate both in known and unknown wireless channels.
A cognitive radio can sense its environment and alter its technical characteristics and operational behavior to benefit both itself and its geographical and spectral neighbors. The ability to sense and respond intelligently distinguishes cognitive radios from fixed or adaptive radios. The characteristics of fixed radios are set at the time of manufacture. An adaptive radio can responds to channel conditions that represent one of a limited set of anticipated events. Adaptive radios use artificial intelligence (AI) algorithms that are basically a series of “IF, THEN, ELSE” algorithms. The radio may fail to take any useful action if it meets conditions that its designers never anticipated.
In contrast, a cognitive radio can respond intelligently to an unanticipated event; i.e., a wireless environment (channel) that it never encountered before. The result is enhanced performance (throughput, quality of service (QOS), and security) for the cognitive radio's network and reduced interference to other networks. The Oxford English Dictionary (OED) defines “cognitive” as “pertaining to cognition, or to the action or process of knowing”, and “cognition” is defined as “the action or faculty of knowing taken in its widest sense, including sensation, perception, conception, etc., as distinguished from feeling and volition”. Given these definitions, the process of sensing an existing wireless channel, evolving a radio's operation to accommodate the perceived wireless channel, and evaluating what happens is appropriately termed a cognitive process. This approach includes both awareness of the wireless channel and judgment of the best possible action to take given this knowledge.
Most cognitive computing systems to date have been based on expert systems and neural networks. Such systems can be quite brittle in the face of unknown environments or else they require extensive training.